Intrusion protection system

ABSTRACT

A tear gas gun is mechanically maintained in a normally cocked position by an electrical resistor connected at one end to a firing pin while the opposite end of the resistor is secured to a stationary surface. The firing pin has a projection extending therefrom which is normally engaged by an electromagnetic latch. The latch is mounted on the plunger of a solenoid energized to cause displacement of the latch to a release position. An electrical control unit has a firing switch connected to the resistor for causing burn-out and disintegration of the resistor upon energization of the solenoid thereby permitting firing action by the firing pin.

United States Patent Iannetti 3,656,658 1 Apr. 18,1972

[72] Inventor: Silve J. lannetti, 735 Moody Street,

Waltham, Mass. 02154 [22] Filed: Oct. 15,1969

[21] Appl. No.: 866,669

[52] U.S. Cl. ..222/5, 42/84, 89/28 A [51] Int. Cl ..B67b 7/24 [58] Field of Search ..1 16/6, 72; 222/5; 169/1 R, 169/2 R; 42/84; 89/135, 28 A; 337/244, 219, 33,

267, 15, 175, 4,5, 8; ZOO/61.08

[56] References Cited UNITED STATES PATENTS 2,794,095 5/1957 Kozacka ..337/5 X 1,294,621 2/1919 Conrad 337/219 X 2,018,810 10/1935 Ronning ..l69/32 X FOREIGN PATENTS OR APPLICATIONS 1,339,377 11/1962 France ..42/84 823,829 11/1959 GreatBritain ..222/5 Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Thomas C. Culp, Jr. Attorney-Clarence A. OBrien and Harvey B. Jacobson ABSTRACT A tear gas gun is mechanically maintained in a normally cocked position by an electrical resistor connected at one end to a firing pin while the opposite end of the resistor is secured to a stationary surface. The firing pin has a projection extending therefrom which is normally engaged by an electromagnetic latch. The latch is mounted on the plunger of a solenoid energized to cause displacement of the latch to a release position. An electrical control unit has a firing switch connected to the resistor for causing bum-out and disintegration of the resistor upon energization of the solenoid thereby permitting firing action by the firing pin.

7 Claims, 3 Drawing Figures The present invention relates to intrusion protection devices and more particularly to an electrically controlled tear gas discharger.

The prior art includes several devices for discharging an incapacitating chemical when tripped by an intruder or in response to an individual fearing ham to his person and property. The most common incapacitating chemical used is tear gas. Generally, the prior art devices include a firing button or trigger for firing a cartridge containing the chemical. In certain previously conceived designs, safety means are not provided for preventing inadvertent firing; In another type of device, a heating wire is employed as a fuse for setting off a charge in a cartridge containing the incapacitating gas. However, the reliability of such a system is low due to the effects of corrosion and oxidation on the heating element. Further, an undesirable time lag occurs between the triggering or energization of the heater coil and the explosion of the charge. This time lag will depend upon the oxidation and corrosion of trigger switch 12 setting off a directed tear gas discharge which would foil the attempt and encourage immediate flight of a would-be assailant or thief. The control unit 14 can be mounted under the dash of the vehicle so that the controls and indicator lights are easily accessible and in full view of the driver. Of course, the present system may be installed in homes, offices, stores and other property where danger of intrusion or theft is present. The actual trigger switch 12 may be the heater element. Accordingly, it is conceivable that injury to persons or property may occur before the incapacitating chemical is set off.

In the present invention, a device receives a cartridge which includes an incapacitating chemical, such as tear gas or the like. The device includes a conventional spring-loaded firing pin. The unique feature of the invention is that the firing pin is held in the cocked position by a trigger in the form of a resistor connected between the firing pin and a stationary surface. The trigger holds the pin in a cocked position until a command signal is received. Upon receipt of the command signal, a large current is caused to flow through the small wattage resistor thereby causing it to disintegrate so that the spring-loaded pin is released causing firing of the cartridge. Virtually instantaneous response to the firing command signal can be realized with the present invention. In order to prevent inadvertent firing, a safety feature is provided in the form of a latch member connected to a solenoid plunger. A latch keeper extends outwardly from the firing pin and is engaged bythe solenoid latch so that inadvertent mechanical breakage of the resistor does not result in firing. However, upon receipt of a command signal, the solenoid is actuated and withdrawal of the latch from the keeper is effected substantially simultaneous with resistor burn-out. The result is the clearing of an unrestrained path for the firing pin resulting in cartridge firing.

In order to determine whether the device is working properly, a test circuit is provided which ensures circuit continuity through the resistor thereby indicating its ready state. A lamp indicator is also furnished to indicate when the system is in a standby condition.

These together with other objects and advantages which will becomes subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claims, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a layout of the electrically connected components comprising the present invention.

FIG. 2 is an internal view of a discharger.

FIG. 3 is an electrical schematic diagram of the present invention. 1

Referring to the figures and more particularly FIG. 1 thereof, reference numeral 10 generally denotesa discharging device for a cartridge containing an incapacitating chemical. For purposes of convenience, the cartridge will be considered to contain tear gas. The tear gas cartridge is fired when a .trigger switch 12 is actuated thereby closing a circuit through a control unit 14. The system is powered by a battery 16 which in the instance of a vehicle would be the dc. vehicle battery.

As pictured in FIG. 1, the system, by way of example, can be used in a taxi. To install the tear gas discharger 10 in an effective manner, the rear side of the driver's backrest may be holin the form of an electric eye or other common sensor which renders the present invention amenable to automatic operation.

Referring to FIG. 2, the tear gas discharger 10 includes a discharge nozzle or barrel 20 which can resemble commercially available tear gas pen dischargers 18. The outward end of the barrel is open at 19 to permit gas expulsion. An intermediate section of barrel 20 includes a rectangular aperture or slot 22 which exposes a length of a rod-like firing pin 24 that is spring-loaded by a biasing spring (not shown) disposed at the opposite end of the barrel. A conventional tear gas cartridge (not shown) is disposed in the open or outward end of the pen to be contacted by the confronting end of the spring-loaded firing pin 24. The opposite end of the firing pin includes a terminal post 26 which connects a first end of a one-fourth watt resistor 28. The opposite end of the resistor is anchored to a second terminal post 30 stationarily fastened to the barrel. The resistor 28 serves as a trigger and normally retains the firing pin 24 in a cocked position.

The present invention also includes a safety device for preventing firing in case the resistor 28 becomes mechanically broken. The safety mechanism includes a projection 32 along an intermediate length of the firing pin 24 that serves as a latch keeper. A U-shaped member 34 is normally positioned in engaging relation with the latch keeper for preventing the firing pin 24 from moving forward. Thus, the U-shaped member 34 serves as a retainer or latch. An opposite end of the latch 34 is mounted on the plunger 36 of a solenoid 38. When a firing signal is generated, as hereinafter described, the solenoid plunger moves downwardly, as viewed in FIG. 2, so that the latch 34 disengages the keeper member 32 thereby removing latch safety action.

Referring to FIG. 3, an electrical circuit is shown which represents the circuit of the present invention. Reference numeral 40 denotes a voltage terminal for powering the system. In the event a conventional automobile battery 16 is employed, the voltage appearing at this point will be +12 v.d.c. Of course, as will be appreciated, the invention will operate equally well with ac. power. Terminal 40 is serially connected with an on-off switch 42. If desired, the switch may be of the type requiring a key to close the switch. A pilot light 44 is connected in parallel between the switch 42 and ground so that it becomes lighted when the switch is turned on thereby indicating to an operator that the system is standing by. The ungrounded terminal of the pilot light 44 is directly connected to the selector contact of switch 42 forming a junction, which is connected to the stationary contact of trigger switch 12. The selector contact of the trigger switch is serially connected to ground through a solenoid 38. In operation of the device, with the on-off switch 42 closed and trigger switch 12 actuated,

lowed to receive the discharger. Thus, in the event of an intrusion or attempted robbery, the vehicle driver may depress current is caused to fiow through solenoid 38 causing displacement of the firing pin retainer or latch 34 thereby releasing the firing mechanism.

The stationary contact of a single pole double throw relay switch 45 is connected to the junction between the solenoid 38 and the selector contact of trigger switch 12. The trigger resistor 28 is connected at one terminal thereof to the selector contact of the switch 45 while the opposite end of the resistor is grounded. Thus, the same current that causes energization of solenoid 38 is diverted by a parallel path through resistor 28 and is of sufficient magnitude to cause disintegration or burnout of the resistor moments after solenoid displacement, whereupon the spring-loaded firing pin 24 shown in FIG. 2 is free to impact against the tear gas cartridge in the barrel 20.

A testing circuit is built into the over-all circuit illustrated in FIG. 3 and serves to check out circuit continuity through the resistor 28, at reduced power conditions so that there is no bum-out of the resistor. This testing circuit includes a springloaded test switch 46 having the fixed terminal connected to the voltage terminal 40. The selector contact of the switch is serially connected to a relay coil 48 having its free end grounded. Thus, upon depression of test switch 46, current is caused to flow through the relay coil 48 so that the aforementioned switch 45, associated with the relay coil 48, is displaced to a second position. In the second position, a series circuit is completed including a reduced dc. voltage supply 54 having a first terminal grounded and a second terminal serially connected to the filament of a continuity indicator lamp 52. The other filament terminal is connected to the second stationary contact of the switch 45. By virtue of the connection between the selector contact of the switch 45 and the trigger resistor 28, a series circuit is completed between the reduced voltage source 54, the continuity indicator 52, and the resistor 28. Therefore, if resistor 28 is electrically ready, current continuity will be indicated by the lighting of indicator 52.

The control unit 14 includes lamp indicators 44 and 52 on a viewing face so that circuit conditions can be monitored by an operator. Also, this face of the control unit mounts the on-off switch 42 and the test switch 46 rendering the switches accessible to the operator. Although the trigger switch 12 is indicated to be of the treadle or foot pedal type, as previously mentioned, this switch may be of an automatic sensing type such as an electric eye. Also, if desired, the trigger switch may be incorporated on the viewing face of the control unit 14.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:

1. In combination with a firing device having a normally cocked firing element, current responsive trigger means connected to the firing element for normally retaining the same in the cocked position, the trigger being responsive to current fiow, and current supply means connected to the trigger means for supplying current to the trigger means causing release of the firing element and operation of the firing device, the trigger means comprising an electrical resistor burned out in response to flow of said current therethrough.

2. In combination with a firing device having a nonnally cocked firing element, current responsive trigger means directly connected to the firing element for normally retaining the same in the cocked position, the trigger means being responsive to current flow, current supply means connected to the trigger means for supplying current to the trigger means causing release of the firing element and operation of the firing device, safety means for preventing movement of the firing element from the cocked position, and means responsive to current flow through the trigger means from said current supply means for disabling the safety means.

3. in combination with a firing mechanism having a barrel and a nonnally cocked firing pin slidably positioned in the barrel, a safety member comprising a latch keeper attached to the firing pin, latch means normally engaging the latch keeper for restraining the pin in a cocked position, electromagnetic means connected to the latch means for withdrawing the same from engagement with the keeper in response to a firing signal, trigger means retaining the pin in the cocked position and responsive to the firing signal for releasing the pin, said trigger means comprising an electrical resistor burned out in response to current there-through and circuit control means comprising a source of voltage potential, a switch connected to the trigger means for gating signal current flow thereto, and means connecting the electromagnetic means in parallel with the trigger means for withdrawal of the latch means substantially immediately before release of the firing in.

4. The mechanism set forth in claim 3 toget er with a crrcurt for testing continuity through the trigger means comprising a second source of reduced voltage potential, test switch means connecting the trigger means and the second source in circuit for supplying reduced power to the trigger means, and indicator means connected in circuit with the trigger means for indicating electrical continuity through the trigger means thereby signifying system readiness.

5. In combination with a firing device having an element biased to a firing position from a cocked position, current conducting resistive means for anchoring the element in said cocked position, a source of electrical energy, signal controlled means connecting said source to the current conducting resistive means for rupturing the same under the bias exerted on the element to release the element for movement to the firing position, and selectively operated test means for conducting current through the resistive means of a magnitude insufficient to release the element.

6. In combination with a firing device having an element biased to a firing position from a cocked position, current conducting resistive means for anchoring the element in said cocked position, a source of electrical energy, signal controlled means connecting said source to the current conducting resistive means for rupturing the same under the bias exerted on the element to release the element for movement to the firing position, mechanical latch means holding the element in said cocked position, and electromagnetic means connected in parallel with the current conducting resistive means for withdrawal of the latch means prior to said rupturing of the current conducting resistive means.

7. The combination of claim 6 including selectively operated test means for supplying reduced current to the resistance means insufficient to cause rupture thereof and relay means responsive to said supply of the reduced current for disconnecting the electromagnetic means from the resistive means. 

1. In combination with a firing device having a normally cocked firing element, current responsive trigger means connected to the firing element for normally retaining the same in the cocked position, the trigger being responsive to current flow, and current supply means connected to the trigger means for supplying current to the trigger means causing release of the firing element and operation of the firing device, the trigger means comprising an electrical resistor burned out in response to flow of said current therethrough.
 2. In combination with a firing device having a normally cocked firing element, current responsive trigger means directly connected to the firing element for normally retaining the same in the cocked position, the trigger means being responsive to current flow, current supply means connected to the trigger means for supplying current to the trigger means causing release of the firing element and operation of the firing device, safety means for preventing movement of the firing element from the cocked position, and means responsive to current flow through the trigger means from said current supply means for disabling the safety means.
 3. In combination with a firing mechanism having a barrel and a normally cocked firing pin slidably positioned in the barrel, a safety member comprising a latch keeper attached to the firing pin, latch means normally engaging the latch keeper for restraining the pin in a cocked position, electromagnetic means connected to the latch means for withdrawing the same from engagement with the keeper in response to a firing signal, trigger means retaining the pin in the cocked position and responsive to the firing signal for releasing the pin, said trigger means comprising an electrical resistor burned out in response to current there-through and circuit control means comprising a source of voltage potential, a switch connected to the trigger means for gating signal current flow thereto, and means connecting the electromagnetic means in parallel with the trigger means for withdrawal of the latch means substantially immediately before release of the firing pin.
 4. The mechanism set forth in claim 3 together with a circuit for testing continuity through the trigger means comprising a second source of reduced voltage potential, test switch means connecting the trigger means and the second source in circuit for supplying reduced power to the trigger means, and indicator means connected in circuit with the trigger means for indicating electrical continuity through the trigger means thereby signifying system readiness.
 5. In combination with a firing device having an element biased to a firing position from a cocked position, current conducting resistive means for anchoring the element in said cocked position, a source of electrical energy, signal controlled means connecting said source to the current conducting resistive means for rupturing the same under the bias exerted on the element to release the element for movement to the firing position, and selectively operated test means for conducting current through the resistive means of a magnitude insufficient to release the element.
 6. In combination with a firing device having an element biased to a firing position from a cocked position, current conducting resistive means for anchoring the element in said cocked position, a source of electrical energy, signal controlled means connecting said source to the current conducting resistive means for rupturing the same under the bias exerted on the element to release the element for movement to the firing position, mechanical latch means holding the element in said cocked position, and electromagnetic Means connected in parallel with the current conducting resistive means for withdrawal of the latch means prior to said rupturing of the current conducting resistive means.
 7. The combination of claim 6 including selectively operated test means for supplying reduced current to the resistance means insufficient to cause rupture thereof and relay means responsive to said supply of the reduced current for disconnecting the electromagnetic means from the resistive means. 